1. Field of the Invention
The invention relates to an actuating drive.
Such actuating drives are advantageously used in the heating, ventilating and air-conditioning art for the actuation of control members such as ventilation flaps, valves and the like.
2. Description of the Prior Art
A housing for an actuating drive of that kind must protect electromechanical and electronic components of the actuating drive from fouling and splashed water and in that respect must also comply with certain standards.
An actuating drive is known for example from the data specification sheet CM2N4613D from Siemens Building Technologies.
Further housings which can protect electromechanical or electronic components or units from contamination or splashed water have been proposed for example in DE 39 27 528 A, GB 975 059 A or EP 777 407 A.
The known housings however suffer from the disadvantage that, to achieve the required sealing integrity, they have additional sealing elements such as sealing rings, cords or strips which are fitted in appropriate grooves in the housings. It is also known for joints of a housing to be sealed off with pastes of various kinds. Known means for affording sealing integrity however involve at least one of the disadvantages listed below:
The sealing element ages and has to be replaced.
The sealing element has to be precisely adapted to the shape of the housing portion and carefully placed.
The sealing element has to be replaced after the housing has been opened.
The housing is gas-tightly closed by the sealing element so that condensation water can form in the interior of the housing, which no longer guarantees the required reliability and security of the actuating drive.
The object of the invention is to propose for an actuating drive a housing with sealing means, in which at least some of the above-listed disadvantages do not occur.
In accordance with the invention, there is provided an actuating drive comprising a housing which has a first housing portion and a second housing portion, wherein:
the two housing portions each have a respective edge with a respective end face and the two end faces are in mutually opposite relationship when the two housing portions are assembled;
the first housing portion and the second housing portion can be releasably and directly assembled together;
when the two housing portions are assembled, first, second and third zones which act in different ways are formed between the two end faces;
the first zone in which the two housing portions are in contact with each other is formed on the housing towards the exterior;
the second zone has a passage and is formed beside the first zone towards the interior; and
the passage of the second zone in the housing is closed towards an internal space of the housing by the third zone in which the two housing portions are not in contact with each other, and the spacing between the two housing portions in the third zone is such that any water present in the second zone, by virtue of surface tension effects, cannot flow beyond the third zone into the internal space of the housing.
Advantageous features are set forth in the dependent claims.